<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <input type="button" value="btn" @click="flag=!flag">
        <!-- v-if的特点都会重新删除或创建元素 -->
        <h3 v-if="flag">这是用v-if控制的元素</h3>
        <!-- v-show每次都会修改DOM的display元素的值 -->
        <h3 v-show="flag">这是用v-show控制的元素</h3>
    </div>
    <script>
            var vm = new Vue({
                el: '#app',
                data: {
                    flag: true
                },
                methods: {
                }
            });
        </script>
</body>
</html>